Critical Appraisal Of The Literature

Thousands of articles regarding complications of pregnancy have been published in the medical literature. For example, a September 2003 MEDLINE search using PubMed as the gateway and using the MeSH heading “Pregnancy, Ectopic,” with the search limited to human studies, articles published in English, and those articles with published abstracts, yielded 8008 articles.2 Obviously, with this extensive body of literature, identifying articles relevant to the practice of emergency medicine can be daunting.

There have been several interesting and potentially important papers published recently. Kohn et al performed a retrospective medical record review of 730 women who presented to an urban ED with abdominal pain, vaginal bleeding, or both and a non-zero quantitative ß-hCG.3 In this cohort, 13% of the women were ultimately diagnosed with ectopic pregnancies. Although the ß-hCG was not an excellent discriminator between ectopic and normal pregnancies, a ß-hCG value less than 1500 mIU/mL was more than twice as likely to be seen in women with ectopic pregnancies than in those with normal pregnancies (positive likelihood ratio, 2.24).

A similar type of analysis was published in 1997 by Dart et al, who performed a retrospective medical record review including 194 women with abdominal pain, vaginal bleeding, or both, but this study evaluated a ßhCG threshold of greater than 3000 mIU/mL and included ultrasonography in the analysis.4 In this study, none of 74 patients with a ß-hCG level greater than 3000 mIU/mL and the absence of a gestational sac identified on ultrasonography were ultimately determined to have a normal intrauterine pregnancy. In 1998, Buckley et al published a study of 486 prospectively enrolled stable first-trimester pregnant women who presented to an ED with abdominal pain, vaginal bleeding, or both. They developed a clinical prediction model for the ED diagnosis of ectopic pregnancy.5 Utilizing recursive partitioning, a clinical decision prediction model was developed that was based in part on abdominal peritoneal signs, cervical motion tenderness, fetal heart tones, tissue at the cervical os, and the absence of pain other than midline menstruallike cramping. This type of clinical decision rule awaits prospective validation in an independent sample before its clinical use can be considered.

In 1998, Valley et al published a prospective observational study of the utility of a serum progesterone level in identifying ectopic pregnancy in a convenience sample of 300 women at risk for ectopic pregnancy presenting to their ED for care.6 These authors concluded that a serum progesterone level could not effectively discriminate ectopic pregnancy from spontaneous abortion in these women. There are now quite a few studies that are well-designed and have fairly large numbers of subjects. Ongoing research is being driven by changes in ultrasound technology, including the ED use of color-flow Doppler studies7 and the increased focus on non-laparoscopic approaches to both diagnosis and treatment.8-10

Clinical Policies

The American College of Emergency Physicians (ACEP) has published three clinical policies related to the care of pregnant women in the first trimester who present to the ED with abdominal pain, vaginal bleeding, or both. The first is titled “Clinical Policy for the Initial Approach to Patients Presenting with a Chief Complaint of Vaginal Bleeding.”11 This practice guideline provides a general approach to the patient with vaginal bleeding but fails to provide a clear evidence-based approach to management decisions. The importance of ß-hCG and Rh testing in the ED is emphasized. Sample discharge instructions and quality assurance forms are included. This clinical policy is general in its format, and therefore may be of limited value in developing specific clinical strategies in the ED. The second ACEP clinical policy is titled, “Critical Issues for the Initial Evaluation and Management of Patients Presenting with a Chief Complaint of Non-traumatic Abdominal Pain.”12 This practice guideline is also quite general and emphasizes basic principles like the importance of ß-hCG testing in the ED. The third ACEP clinical policy is titled “Critical Issues in the Initial Evaluation and Management of Patients Presenting to the Emergency Department in Early Pregnancy.”13 This policy takes an evidence-based approach and focuses on six clinical questions ranging from the role of ultrasound when the ß-hCG value is less than 1000 mIU/mL to the indications for anti-D immunoglobulin (i.e., RhoGAM) in the symptomatic early pregnancy. The discussion of indications for anti-D immunoglobulin is particularly well done.

The Cochrane Database also published systematic reviews of diagnostic strategies and interventions for the management of ectopic pregnancy.14,15 These documents provide a comprehensive review of the current literature related to ectopic pregnancy.

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